I've read a lot on here about this device and finally found one today in JY in a 1986 F150
so I figured I'd take some pix and write it up as a FAQ.

Background & Naming:

First of all, its name... I get that out of the 1981 Factory Wiring Diagrams manual:






Purpose:

This device lights the EMISSIONS light on the dashboard of some 1981-1987 (?)
F-series, Broncos, Rangers, probably a host of other Ford products of the time.

The light comes on every ~60,000 miles as a reminder to service the emissions
control system, nothing more.

Identification:

This particular device I found is plastic (I understand some are metal) and is bigger than I
had imagined, about 3" long X 2.5" wide (including mounting ears and electrical
connector):



Note I broke off one of the mounting wings, I didn't have a screwdriver on me to remove
it in a correct & proper fashion; the red bulb socket pictured above is just for reference.

This particular unit has 6H11B printed on it;
embossed in the plastic is: E5TF-12B514-AA;
also embossed on the top is:

LECTRON
ROCH, MI.

Location:

This particular one was located underneath the dash, screwed to a support bracket near
the headlight & wiper *****. It was hard to find because of that location, it was facing
the wiper switch and the bracket hides it.

Here is a picture of its location:


I understand on Bronco IIs it has been known to be located behind the glove compartment:
https://www.ford-trucks.com/forums/1...l#post10090316

Resetting it:

<!-- Wise Ones in this forum tell us the button merely needs to be pressed, a dental pick
or small screwdriver or framing nail would fit in the hole:-->
There is a Reset button recessed in a hole, this may be covered with tape or a sticker if
it has never been reset before.



According to Internet-based wisdom, apparently one depresses the button, then turns the
key to RUN, keep depressing for ~5 seconds and then release; the light should remain
on for 2-5 seconds after which time it will shut off:

Ford Questions - how do i get the emissions light to go off - JustAnswer
For google:

6H11B E5TF-12B514-AA Implied Mileage Sensor controls Emissions light in dash

 

You'll also see it in other wiring diagrams as the Infered Mileage Sensor.

 

I have heard the main purpose of this was so the owner would bring it in and get the EGR cleaned or replaced. The dealer would reset the light while they were doing the emissions maintenance.

 

Yep, for other than to get you to take it to the dealer, it's really useless.

I have the wiring diagrams for 1973-1989. I did some checking.

On the 1982 and 1983 diagrams, it shows this Implied Mileage Sensor and it states, "All with 5.0L engine, California only". EEC-III, Duraspark III diagram. Wire colors, Tan/Light Green Hash, Red, and Black/Light Green Dot.

The 1981 does not show this legend, but it is shown in the EEC-III, Duarspark-III diagram, which is a California only smog control torture device.

So to be more acurate, before 1984 it seems if you live in California, and you have a 5.0L with EEC-III, DS-III, you have this Implied Mileage Sensor as well. It only became 50 state with the EEC-IV, TFI-IV, then again, select models. This is infered by the wiring diagrams I have.

So learn something new.

The 1984 Diagram shows the Implied mileage sensor as a "I.M.S." only. Color Wires are Black/Light Green, Red, and Dark Green/White.

 

Can you tell us which years this was installed? I editted the above post a bit to
reflect your information and would like to edit it some more.

Also clarified what it takes to rest it based on what else 'net tells us.

 

Implied Mileage Sensor...

It looks like 1981-1983 California models with a 302 and EEC-III, DS-III. Also the first year of EEC-III, Duraspark-III, according to my diagrams, is 1981. This is using the 1980 through 1986 diagrams as comparisons with each other.

The Ford Cars could have had it earlier than 1981 however.


I also looked up the colors:

Red/Yellow Stripe
Black
Yellow/Black

What is pictured above is not the Implied Mileage sensor. It is the Extended Useful Life Sensor. First year of extended useful life sensor is in the 1985 diagram.

What is the difference? Not sure yet. Still checking... But since the 1985 diagram has wiring for both the "I.M.S." and "E.U.L.F." then it has to be something.

I'll try and scan the relevant area of the diagrams sometime today, (They are huge) so we all can get a clearer picture of this conundrum. So watch this space.

 

My 86 F350 has a functioning ( light goes out after start ) emissions light, even though I have a Holley with no air pump or emissions lines.
Would this be the same thing ?
1986 F350, 5.8L

Gonna see if I can see the module....be back

I have a similar item ( it is substantial ) on the u-shaped bracket that goes around the dimmer and wiper switch.
it is next to the wiper switch, on the bracket.
Could not feel a reset button.
Bracket mounting "ears" are identical.

Just curious as my truck is an 86...didn't really understand which years "have it", according too the diagrams.

Thanks for the info though....cause I was curious exactly what emissions I had with none really evident

Nick

 

Extended Useful Life Sensor? How odd. If we can confirm that, I'll edit the thread
some more.

I have no idea where to locate that in the parts catalog but Bill will be back Tuesday (I
think).

fluknick - the switches are recessed in a hole, there's not much to feel. A mirror on a stick
might be helpful.

 

Alright I got the Diagrams Downloaded. Whew....

-----------------------------------

1985 Instrument Cluster and Sending Unit wiring diagram.

Shows the Extended Usefull Life Sensor, and it matches the wiring on the device in question. It also has a lamp. 1986 is identical, and 1984 is virtually identical except the Extended Usefull Life Sensor is not in the 1984 diagram.

http://i447.photobucket.com/albums/q...randguages.jpg

--------------------------------

1984 EEC-IV/TFI-IV diagram for the 5.0L EFI Engine. This shows the Implied Mileage Sensor. 1985 and 1986 identical.

http://i447.photobucket.com/albums/q...VEEC-IV50L.jpg


--------------------------------------------

1982 EEC-III/DS-III diagram. Shows the Implied Mileage sensor. 1983 identical. 1981 Identical except for the legend (All 5.0L Engines California Only) is missing.

http://i447.photobucket.com/albums/q...m1981-1983.jpg

=========================

So with this information, I would safely conclude the the Implied Mileage sensor and the Extended Usefull Life Sensor are two different things.

 

Hmmmm... Yes, it seems you are right.

That means I'll have to make a NEW thread like this when I find THE REAL DEAL!

Well, wait... this is getting more involved than I thought it would.... That button, is that still
something that can be reset to cause that light in the top-left corner to shut off? I have no
idea what was on the cluster trim (somebody had already removed that) and just looked at
the wire colors and figured Ah Ha!!!! There was another truck in the JY but it just had a
dangling connector in that area, seems a PO had already disabled the thing.

I'm still wondering what this EUL sensor is and if there is still, in fact, an additional device
on these later-year trucks that would qualify as being an IMS? I'd think not but what do I
know....

I think I'm gonna have to make notes to carry with me and pay particular attention to the
years of trucks I'm snooping in. My primary motivation for this was helping a guy with a
1986 Bronco II and his Emissions light just came on.

Maybe instead of making a new thread I'll just rename this one and refer to generic
modules that can cause that light to come on....

 

I have a similar setup in my '87, except the box is more square cornered and located up between the steering column and the radio.
AFAIK, it is just a runtime clock.
The EMISS light comes on in my truck every 60-75k and I just use a paperclip to reset the darned thing.

 

Well, I was going through my diagrams and I found this one as well in the 1984 diagram.

Useful Life Sensor. I did not notice it before as it's in a different spot on the diagram.

http://i447.photobucket.com/albums/q...nitdiagram.jpg


What I'm thinking is the Usefull Life Sensor, and the Extended Usefull Life sensor is the same, except the Extended Usefull Life Sensor is resetable. I've heard that the earlier ones were not resetable and had to be replaced as a unit or unplugged. Which this would make sence I suppose calling them different in the diagrams.

These are the ones that turns on the emissions lamps. This would make sence as these are in the instrument cluster and sending unit diagrams, and are not connected to the computer at all.

------------------------

The Implied Mileage sensor doesn't even have a lamp hooked to it in the diagrams, so I think this is something completely different. It only seems to be used on the 5.0L as well.


-------------------------

So to summerize...

Usefull Life, and Extended Usefull Life sensor: This is what turns on the emissions lamp. and what you got pictured. Marked: E5TF-12B514-AA

Implied Mileage Sensor: I'm pretty positive, Is not what turns on the Emissions lamp, as there is no lamp hooked to it at all. Do not know what it does yet.

 

Yes, 1987 is the last year The extended usefull life sensor is shown in the diagrams as well.

So it's looking like 1984-1987 is the year range for the emissions lamp, and Regular or Extended Usefull lamp sensor. 1988 is the first year for the Check Engine type lamp, so this makes sense.

The Implied mileage sensor I don't know what it does yet.

 

Allow me to present, from acreage of the play-ground known as the front bench seat:
Emission light of the Beast !!! Ha Ha Haaaa !!!



Just a little buffoonery

Great info as always !
Nick

 

I found another one of these doodads, this one had apparently never been reset: